Means of producing a smooth dense surface on concrete deposited against forms



p 1936. w. A. WHITING 2,055,514

MEANS OF PRODUCING A SMOOTH DENSE SURFACE 0N CONCRETE DEPOSITED AGAINST FORMS Filed June 25, 1935 J4 20 Pd P I 1 24 Z7 v I L- tr I {r J 17' lg fi 3mm ,fl w. 6; m M 42 W Patented Sept; 29, 1936 PATENT OFFICE MEANS OF PRODUCING A SMOOTH DENSE SURFACE ON CONCRETE DE POSITED AGAINST FORMS William A. Whiting. Southgate, CaliL, assignor to American Concrete and Steel Pipe Company, a corporation of Delaware Application June 25, 1935, Serial No. 28,272 c (01. 25-1) It is common practice in the building of structures or articles of concrete to use forms to properly shape the concrete and retain the concrete during the time of setting. Upon removal of the forms from the concrete the concrete face or surface usually contains a great number of air and water pockets of varying size due to the fact that there is no practical way of tamping the concrete against the forms, particularly when the forms are of large size. Spading, vibrating and other means have been resorted to but as far as I am aware none of the known methods have been successful in entirely eliminating the air pockets from the surface of the concrete. It is a principal object of my invention to produce a method and means whereby such air pockets may be eliminated in a practical and economical manner.

I have found that by rotating .a rodin the concrete adjacent the form that the desired result may be obtained but that in using the ordinary rod it is impossible by manual means to move the rod laterally through the concrete. I

have found, however, that by using a rod having Y a series of projections on one side or a rod which is rotated eccentrically of its longitudinal central axis that such a rod; being rotated, will propel itself laterally along the inside of the form. This self propelled rod, I have discovered, moves laterally along the form due to the fact that during its rotation the of! center portions of the rod successfully engage the concrete next to the form and the concrete in the body of the material and due to the fact that there is less resistance in the concrete next to the form than in the concrete in the body of the material, the rod propels itself .along the inside of the form thoroughly tamping the concrete and removing the air bubbles from the portion of the concrete surface against the forms.

Referring to the drawing which is for illustrative purposes only;

Fig. 1 is a face view of a form, a portion of the form being broken away to show the body of con- 5 crete with the rod in position therein. Fig. 2 is a plan view of the device shown in Fig. 1 with the rod in section. 1

Figs. 3 to 7 inclusive show different forms of rod, and

Fig. 8 is a cross sectional view of the rod shown in Fig. 7. c

Referring more particularly to the drawing, l l

indicates a form which may be of any common type and I2 concrete in the form. l3 designates the tamping rod of the type shown in Figs. 1 to 3 inclusive and consists of a straight bar or rod to one side of which has been secured as by welding or in any other suitable manner, blocks or fins II. The upper end of the rod I3 is secured to the shaft of the motor I5 by any suitable means such as by a socket and bolt diagrammatically illustrated at IS in Fig. 1. In the form of bar shown in Fig. 4 the bar is deformed with offset portions ii on one side thereof. In the form shown ln'Fig. 5 the bar has both the blocks 14 and an offset portion II. In the form shown in Fig. 6 the bar is formed with a single oifset portion IT at one side thereof, and in the form of bar shown in Figs. '7 and 8 the bar consists of a body portion 20 having a fin or web 21 15 extending throughout its length on one side thereof.

Theoperation of tamping the surface of the concrete next to the form is accomplished by inserting the bar downwardly into the concrete in substantially the position shown in Fig. 1 with 20 the bar near the inner face of the form as shown in Fig. 2. The bar is then rotated by means of the motor or other suitable power means and the concrete thoroughly tamped adjacent the form, the motor being held by means of handles i5. 25 The rotation of the bar brings the projections on the bar or the offset portions or eccentric portions, as the case may be, successively into contact with the concrete adjacent the form and away from the form and due to the different resistance of the concrete, at such points, the bar propels itself laterally along the inner face of the form thereby removing all voids and air and water holes from the face of the concrete next to the forms. I have found that barsof great length may be readily used in the manner above described with little or no effort on the part of the operator whereas it has been impossible with bars of ordinary form to he moved through the concrete even with great exertion on the part of the operator where such bars were greater than two or three feet in length.

I claim as my invention:

1. A device for producing a smooth dense surface on concrete deposited against forms comprising: a rod having a projected portion at one side of its longitudinal axis; and means coaxial with the longitudinal axis of the rod for rotating said rod in the concrete adjacent the form.

2. A device for producing a smooth dense surface on concrete deposited against forms comprising: a deformed rod having a portion extended at one side from its longitudinal axis; and means coaxial with the longitudinal axis of the 55 rod for rotating the rod in the concrete adjacent the form.

3. A device for producing a smooth dense surface on concrete deposited against forms comprising: a rod, projections on said rod at one side thereof, and means for rotating said rod on its longitudinal axis in the concrete adjacent the form.

4. A device for producing a smooth dense surface on concrete deposited against forms comprising: a rod, and means for rotating said rod eccentricaliy of its cr ss sectional center in the concrete adjacent the form.

v '5. A device for producing a smooth dense surprising: a rod, and means for rotating said rod eccentrically of its cross sectional center in the concrete adjacent the form; said means consisting of a motor and means for coupling said rod to the motor.

WILLIAMAWHI'I'HQ'G. 

